Stereoscopic imaging systems utilizing solid-state illumination and passive glasses

ABSTRACT

A stereoscopic display system employs narrowband illumination light beams and passive glasses with built-in interference filters. The system is also compatible with multiple viewing functions.

TECHNICAL FIELD

The technical field of the examples to be disclosed in the followingsections relates to the art of display systems, and more particularly,to the field of stereoscopic imaging systems using solid-stateillumination and passive glasses.

BACKGROUND OF THE INVENTION

Traditional stereoscopic imaging systems for visualization of virtualobjects use active shutter glasses and passive polarization glasses.Active shutter glasses incorporate left and right shutters that aresynchronized to the sets of images for left and right eyes (left andright images). This approach, however, adds cost and introducesartificial effects, such as flickers as each side of the glasses turnson and off.

Passive glasses work in systems employing polarized light andincorporate left and right polarizers that are typically offset by 90°degrees. Due to the polarization, brightness and optical efficiency canbe significantly reduced.

Therefore, there exists a need for cost effective displays capable ofreproducing stereoscopic images with high brightness and opticalefficiency.

SUMMARY

In an example, a method is disclosed herein. The method comprises:producing first and second light beams that are composed of differentnumbers of colors; modulating the first and second light beams basedupon first and second sets of image data that are respectively derivedfrom first and second sets of images; and passing the modulated firstand second light beams through a pair of passive glasses with built-infirst and second interference filters for viewing such that themodulated first light beam is capable of passing through andsubstantially only the first interference filter; and such that themodulated second light beam is capable of passing through andsubstantially only the second interference filter.

In another example, a system for use in producing a stereoscopic imageis disclosed herein. The system comprises: an illumination systemcapable of producing first and second sets of light beams, wherein thewavelengths of light of the first set are not substantially overlappedwith the wavelengths of light of the second set, and wherein the firstset light beams comprises a different number of colors than the secondlight beam; a color processor capable of scaling the colors of the imageinto a consistent and unique color space; an image engine forre-producing a set of images derived from the stereoscopic image bymodulating the light beams based upon the stereoscopic image; and apassive glass with a built-in interference filter for separating the setof images such that different images of the image set can arrive atdifferent eyes of the viewer.

In yet another example, a method is disclosed herein. The methodcomprises: producing first and second narrowband light beams; modulatingthe first and second light beams based upon first and second sets ofimage data that are respectively derived from first and second sets ofimages; passing the modulated first and second light beams through apair of passive glasses with built-in first and second interferencefilters for viewing such that the modulated first light beam is capableof passing through and substantially only the first interference filter;and such that the modulated second light beam is capable of passingthrough and substantially only the second interference filter; anddelivering the re-produced first set of images to a first viewer, andthe second set of images to the second viewer for viewing.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating an exemplary display system;

FIG. 2 is a block diagram showing an exemplary structure of theillumination system in FIG. 1;

FIG. 3 a illustrates an exemplary structure of the right light source inFIG.2;

FIG. 3 b illustrates an exemplary structure of the left light source inFIG.2;

FIG. 4 illustrates an exemplary stereoscopic imaging method using twoprimary color triplets generated by the illumination system of FIG. 3 aand FIG. 3 b with each color triplet having red, green, and blue color;

FIG. 5 illustrates the color space used in the imaging methodillustrated in FIG. 4;

FIG. 6 a illustrates another exemplary structure of the right lightsource in FIG.2;

FIG. 6 b illustrates another exemplary structure of the left lightsource in FIG.2;

FIG. 7 illustrates an exemplary stereoscopic imaging method using twoprimary color triplets generated by the illumination system of FIG. 3 aand FIG. 3 b with asymmetric number of primary colors for right and lefteye imaging;

FIG. 8 illustrates the color space used in the imaging methodillustrated in FIG. 7;

FIG. 9 illustrates yet another exemplary stereoscopic display system ofthe invention which provides independent viewing experience for separateviewers;

FIG. 10 illustrates yet another exemplary stereoscopic display system ofthe invention which employs multiple image engines for generatingstereoscopic images;

FIG. 11 illustrates yet another exemplary stereoscopic display system ofthe invention which employs multiple image engines for generatingstereoscopic images; and

FIG. 12 illustrates yet another exemplary stereoscopic display system ofthe invention which employs multiple image engines for generatingstereoscopic images.

DETAILED DESCRIPTION OF SELECTED EXAMPLES

Examples disclosed herein is a stereoscopic imaging system that usesillumination light with narrowband spectrum to generate stereoscopicimages such that the generated images can be visualized using passiveglasses, in particular, passive glasses integrated with interferencefilter technology (Infitech). By narrowband, it is meant that thefull-with at half maximum (FWHM) of the light spectrum is 100 nm orless, more preferably 50 nm or less, and 30 nm or less.

Turning to the drawings, FIG. 1 is a diagram schematically illustratesan exemplary stereoscopic display system within the scope of theinvention. Stereoscopic imaging system 100 in this particular examplecomprises illumination system 102, image engine 110, synchronizationunit 112, color processor, right lens filter 114, and left lens filter116.

Illumination system 102 is capable of emitting narrowband illuminationlight beams with different waveband spectra. Subject to the constraintthat the maximum number of allowable light beams with different wavebandspectra is determined by the interference characteristics of theInfitech filter of the passive glass, the number of light beams withdifferent waveband spectra can be determined by the desired number ofimaging channels with each channel transporting a sequence of images fora certain Infitech filter. As an example shown in the figure,dual-imaging channels, i.e. right image light and left image light, canbe provided in compatible with the end right and left lens filters 114and 116. Image information delivered by the right image light and passedthrough right lens filter 114 is collected by right eye 118 of theviewer; and image information delivered by the left image light andpassed through left lens filter 116 is collected by left eye 120 of theviewer. In other alternatives, more than two imaging channels, and morethan two separate illumination light beams with different wavebandspectra can be provided, which will be discussed afterwards.

The illumination system may have one or multiple light source units forproviding light beams of different spectrums. An example is shown inFIG. 2. Referring to FIG. 2, illumination system 102 comprises rightsource unit 122 and left source unit 124 for providing illuminationlight beams for right image channel and left image channels,respectively. In other alternatives, the illumination system may haveany suitable number of light source units. Though not required, thesolid-state light source units (e.g. 122 and 124) of the illuminationsystem can be composed of solid-state light sources, such as lasers,LEDs, or any other suitable solid-state light sources capable ofemitting narrowband light beams. Each light source unit preferablycomprises light sources emitting a set of primary colors, such as red,green, and blue. For each color, there can be multiple light sourcesespecially for rendering a desired waveband spectrum. For example, a setof light sources whose spectrums are substantially around one of theprimary colors (e.g. red) but are sequentially shifted a small amount(e.g. 5 nm or less) can be used so as to obtain a desired bandwidth withsubstantially flat top.

In an alternative configuration, the illumination system (102) may havelight source(s) not specifically designed for particular imagingchannels. In this instance, for example when only one light source unitis provided, Infitech filters can be coupled to the light source unit soas to produce light beams with different (complementary) wavebandspectrums. The produced light beams can then be used to deliver imageinformation to the viewer.

Referring again to FIG. 1, the illumination light beams from theillumination system (102) are directed to image engine 110. The imageengine can be any suitable devices capable of re-producing images. Forexample, the image engine may comprise reflective and deflectablemicromirror devices, liquid-crystal cells (LCD), or liquid crystal onsilicon cells (LCOS). Depending upon different optical configurations,the system can be a front- and rear-projection systems or other displaysystems, such as backlit displays.

The image engine (110) modulates the incident light beam (or multiplebeams) based upon a set of image data derived from the correspondingimages. For example, when right and left light beams are sequentiallydirected to the image engine, image data derived from right and leftimages (104 and 106) are sequentially delivered to the image enginethrough color processor 108 for modulating the incident light beams. Theright and left images (104 and 106) can be generated by a separatemodule that is not shown in the figure.

To properly producing desired images, operations of the image engine,light sources of the illumination system, and feeding of the image dataof right and left images are desired to be synchronized. For example,during the time periods when right light source is turned on while theleft light source is turn off, the right light beams illuminate theimage engine. Image data of the right images are fed into the imageengine. The image engine then modulated the incident right light beamsbased on the image data of the right images so as to properly reproduceright images. The re-produced right images after the image engine areprojected (e.g. by projection lens) to the passive Infitech glasses. Atthe passive Infitech glasses, the right images carried by the rightlight beams are passed through the right lens filter (114) and stoppedby the left lens filter (116). Accordingly, only right side eye 118 ofthe viewer receives right images.

At time periods when the right light source is turned off; and the leftlight source is turned on, left image data derived from the left imagesare delivered to the image engine that re-produces left-images based onthe left image data. The re-produced image data are then projected tothe passive Infitech glasses (e.g. by projection lens); and pass throughthe left lens filter 116.

By sequentially turning on and off right and left light sources, andfeeding image data of right and left images onto the image engine,re-produced right and left images can be sequentially delivered to rightand left eyes 118 and 120, thus generating stereoscopic virtual objects.The above synchronization of the light sources, image feeding, andoperation of the image engine can be accomplished by synchronizationunit 112.

Other than sequentially re-producing right and left images as discussedabove, right and left images can be simultaneously produced. In thisexample, multiple image engines are provided, which will be discussedafterwards with reference to FIG. 10.

As an example, FIG. 3 a, FIG. 3 b, and FIG. 4 schematically demonstrateexemplary image channels of the display system in FIG. 1 for producingstereoscopic images. As shown in FIG. 3 a, right light source unit 122comprises light sources 126, 128, and 130 for producing narrowbandprimary colors red, green, and blue, respectively. Left slight sourceunit 124 of FIG. 3 b comprises light sources 132, 134, and 136 forproducing another set of primary colors of red, green, and blue,respectively. It is noted that each color of each light source may havemultiple light sources with identical spectrum or with small differencesin spectrums.

In the top of FIG. 4, dual primary color triplets B_(R)-G_(R)-R_(R) andB_(L)-G_(L)-R_(L) for right imaging are illustrated therein. Each of theprimary colors, red, green, blue, comprises substantiallynon-overlapping wavebands for right and left imaging. Specifically,B_(R) and B_(L) lie in the blue color range; G_(R) and G_(L) lie in thegreen color range; and R_(R) and R_(L) lie in the red color range.Wavebands B_(R), G_(R), and R_(R) form the color triplet for formingright images; and color wavebands B_(L), G_(L), and R_(L) form the colortriplet for forming left images.

The middle and bottom of FIG. 4, the dual color triplets after thepassive Infitech glasses are schematically illustrated. As shown in themiddle of FIG. 4, the color triplet B_(R)-G_(R)-R_(R) for the rightimages is passed through the right lens filter (e.g. 114 in FIG. 1); andthe color triplet B_(L)-G_(L)-R_(L) for left images are stopped by theright lens filter. As a result, only the right images carried by thecolor triplet B_(R)-G_(R)-R_(R) can arrive at the right eye of theviewer after the passive Infitech filter. The color tripletB_(L)-G_(L)-R_(L) for left images is passed through the left Infitechfilter but stopped by the right Infitech filter—resulting in only leftimages arriving at the left side eye of the viewer. The left and rightimages are then integrated by the viewer's eyes so as to form thevirtual stereoscopic object.

FIG. 5 schematically illustrates the color spaces in the color gamut.Blue_(right), Green_(right), and Red_(right) represent the saturatecolors of the color triplet B_(R)-G_(R)-R_(R); and together define thecolor space for the right images, which is represented by the areasurrounded by solid line triangle. Blue_(left), Green_(left), andRed_(left) represent the saturate colors of the color tripletB_(L)-G_(L)-R_(L); and together define the color space for the leftimages, which is represented by the area surrounded by dashed linetriangle. This non-uniform color spaces for right and left images maycause annoying visual effect to the viewer, such as color displacementeffect. In the example as shown in FIG. 5, the right eye of the viewermay feel that right images are greenish; while the left images arered-ish or blue-ish. In order to maintain a consistent color space forthe right and left images perceived by the viewers, a unique color spaceis defined as illustrated in shaded area in FIG. 5. This unique colorspace is for both right and left imaging. Input right and left colorimages are processed (e.g. by color processor 108 in FIG. 1) so as toscale the primary colors of the right and left images into the uniquecolor space by mixing colors. For example, the green color of the rightimages outside the shaded area can be mixed with an amount of blue andred colors. The red color of the left images when outside the shadedarea can be mixed with an amount of green and blue.

As afore mentioned, the illumination light beams may or may not have thesame number of primary colors. In particular, a beam of illuminationlight can be primary color triplet; whereas another beam of illuminationlight can be color multiplet with more than three colors, such as colortetrad and color quintuplet. FIG. 6 a and FIG. 6B schematicallyillustrate a such example. Referring to FIG. 6 a, right light source 138unit of the illumination system 102 (in FIG. 1) may comprise lightsources 126, 128, 130, 140, and 142 for emitting red, green, blue, cyan,and yellow colors. It is noted that cyan and yellow, or any one or morecolors of red, green, and blue, in this example, can be replaced byother colors, such as white and magenta. Moreover, other colors, such aswhite and magenta can be added to the right light source. Left lightsource unit 124 can be the same as that shown in FIG. 3 b, whichcomprises light sources for red, green, and blue color. Of course, theright light source unit 138 may have less number of light sources or canbe the same as that in FIG. 3 a; while left light source unit 124 mayhave more number of light sources.

The spectrums of the colors from the right and left light sources areschematically illustrated in the top plot of FIG. 7. Referring to FIG.7, the right color quintuplet B_(R)-C-G_(R)-Y-R_(R) for right images andleft color triplet B_(L)-G_(L)-R_(L) for left images are illustratedthere on the top of the figure. Additional colors cyan and yellow areadded to enhance the color and whiteness of the perceived images. Thecyan and yellow colors can be generated directly by right light sources,such as solid-state light sources, or can alternatively by mixing colorsfrom red, green, and blue colors (B_(R), G_(R), and R_(R)) of the rightlight sources.

After the passive Infitech glasses as shown in the middle of FIG. 7,B_(R), C, G_(R), Y, R_(R) colors are passed through the right lensfilter (e.g. 114 in FIG. 1); and the color triplet B_(L)-G_(L)-R_(L) forleft images are stopped by the right lens filter. As a result, only theright images carried by the color quintuplet B_(R), C, G_(R), Y, andR_(R) can arrive at the right eye of the viewer after the passiveInfitech filter. The color triplet B_(L)-G_(L)-R_(L) for left images ispassed through the left Infitech filter but stopped by the rightInfitech filter—resulting in only left images arriving at the left sideeye of the viewer. The left and right images are then integrated by theviewer's eyes so as to form the virtual stereoscopic object.

FIG. 8 is a chromaticity diagram schematically illustrating the colorspaces of the quintuplet and triplet colors of FIG. 6 a and FIG. 6 b.Blue_(right), Cyan_(Right), Green_(right), Yellow_(Right), andRed_(right) represent the saturate colors of the color quintupletB_(R)-C-G_(R)-Y-R_(R); and together define the color space for the rightimages, which is represented by the area surrounded by solid linetriangle. Blue_(left), Green_(left), and Red_(left) represent thesaturate colors of the color triplet B_(L)-G_(L)-R_(L); and togetherdefine the color space for the left images, which is represented by thearea surrounded by dashed line triangle. In order to maintain aconsistent color space for the right and left images perceived by theviewers, a unique color space can be defined for both right and leftimaging. Input right and left color images are processed (e.g. by colorprocessor 108 in FIG. 1) so as to scale the primary colors of the rightand left images into the unique color space by mixing colors.

The stereoscopic display systems as described herein are also compatiblewith multiple viewer function, as shown in FIG. 9. Specifically, themaximum number of different viewers simultaneously experiencingdifferent image contents is determined by the characteristicinterference spectrum of the passive Infitech filter and the narrowestcharacteristic bandwidths of the illumination light beams from the lightsources. In this specific example, two imaging channels (correspondingto right and left illumination light beams) are provided by the lightsource. Accordingly, the system can provide two different (though notnecessary) sets of viewing contents to two viewers—image viewer 146 andimage viewer 154. In operation, right illumination light carries imageset A 160 and delivers image set A to eyes 152 (both right and leftsides) of viewer 146 through image A lens filter 150. Light illuminationlight carries image set B 162 and delivers image set B to eyes 158 (bothright and left sides) of viewer 154 through image B lens filter 156, asshown in the figure. In this example, viewers 146 and 154 may notexperience stereoscopic imaging. To provide stereoscopic viewing fordifferent viewers (e.g. 146 and 154) with different contentssimultaneously, multiple imaging channels are created, as shown in FIG.10.

Referring to FIG. 10, the illumination system (102) provides multipleillumination light beams L_(A) ^(r), L_(A) ^(l), L_(B) ^(r), and L_(B)^(l), with different wavelength spectrums having substantially noover-laps therebetween. The light beams L_(A) ^(r), L_(A) ^(l), L_(B)^(r), and L_(B) ^(l) respectively corresponds to the characteristicinterference spectrums of right and left passive Infitech filters ondifferent viewers 146 and 154. Specifically, light beams L_(A) ^(r) canand substantially only can pass through the right lens filter of viewer146; while light beams L_(A) ^(l) can and substantially only can passthrough the left lens filter of viewer 146. Light beams L_(B) ^(r) canand substantially only can pass through the right lens filter of viewer154; while light beams L_(B) ^(l) can and substantially only can passthrough the left lens filter of viewer 154. Image contents are dividedinto groups for different viewers; and the image contents for eachviewer are divided into right and left images for left and right sideeyes of the specific viewer.

In operation, the image engine can modulate each of the light beamsL_(A) ^(r), L_(A) ^(l), L_(B) ^(r), and L_(B) ^(l) sequentially in anydesired orders, but is synchronized with the input images. For example,the image engine can re-produce right and left images for viewers 146and then re-produce left and right images for viewer 154. In thisspecific operation, light beams L_(A) ^(r) and L_(A) ^(l) sequentiallyilluminate the image engine while synchronized by sequentially feedingthe right and left images for viewer A (146) into the image engine, asdiscussed with reference to FIG. 1. The modulated illumination lightcarrying right and left image information for viewer 146 are projectedto passive Infitech filters of viewer 146 wherein light beams L_(A) ^(r)and L_(A) ^(l) separately pass through right and left lens filters ofthe viewer 146. After one or multiple frames of images for viewer A aremodulated and projected to viewer A, image engine can be operated tore-produce images for viewer B 154. During this time period, light beamsL_(B) ^(r) and L_(B) ^(l) sequentially illuminate the image engine whilesynchronized by sequentially feeding the right and left images forviewer B (154) into the image engine. The modulated illumination lightcarrying right and left image information for viewer 154 are projectedto passive Infitech filters of viewer 154 wherein light beams L_(B) ^(r)and L_(B) ^(l) separately pass through right and left lens filters ofthe viewer 154. After modulating one or more frames of images for viewerB, the image engine can turn again to re-produce images for viewer A.The above process is repeated for re-producing images for both viewers.

In an alternative example, image engine can be operated to re-produceright (or left) images for right (or left) side eye of viewer 146followed by re-producing images for right (or left) images for right (orleft) side eye of the different viewer 154, which will not be discussedin detailed herein. Of course, other than single image engine, thestereoscopic system can employ multiple image engines for re-producingimages for separate (or the same) viewer(s). For example, the imageengine 110 in FIG. 10 can be assigned to re-produce images for viewer A146. Another image engine (not shown in the figure) can be provided toreproduce images for viewer 154. In this example, illumination lightbeams L_(A) ^(r) and L_(A) ^(l) preferably illuminates only the imageengine designated to reproduce images for viewer A; and illuminationlight beams L_(B) ^(r) and L_(B) ^(l) preferably illuminates only theimage engine designated to reproduce images for viewer B.

In yet another example, multiple image engines are provided with eachimage engine being assigned to re-produce only a portion of the imagesfor both viewers A and B. For example, an image engine can be assignedto reproduce right images for right side eyes of both viewers 146 and154; while another image engine can be assigned to reproduce left imagesfor left side eyes of both viewers 146 and 154.

Even for one viewer, provision of multiple image engines in the systemcan also be advantageous in imaging performance. An example of suchsystem is schematically illustrated in FIG. 11. Referring to FIG. 11,image engines 110 a and 110 b are provided for respectively reproducingimages for right and left side eyes 118 and 120. For this purpose, rightimages to be re-produced for right side eye of the viewer are deliveredto image engine 110 a; and left images to be re-produced for left sideeye of the viewer are delivered to image engine 110 b. Operations ofimage engines 110 a and 10 b, feeding of the right and left images, andemitting of the illumination light from the illumination system can besynchronized by synchronization unit 113.

Instead of juxtaposing multiple image engines (102 a and 102 b) inparallel on the optical path of the display system for independentlyre-producing images, the multiple image engines can be serially disposedon the optical path of the system, as shown in FIG. 12. Thisconfiguration can be of importance in obtaining high dynamic range (e.g.2000:1 or higher and 10,000:1 or higher) and high resolution. Referringto FIG. 12, image engine 110 a is disposed in front of image engine 110b on the optical path of the system. The two image engines may or maynot have the same resolution or same type of physical pixels. Forexample, one of the image engines may be composed of micromirrorswhereas the other one can be composed of LCD cells, LCOS cells, orplasma cells. The front side image engine is designated to projectimages onto the rear side image engine. As a result, the contrast ratioof each pixel of the reproduce image (perceived by viewer's eyes) is aproduct of the natural contrast ratios of the two image engines. Byoffsetting the pixel arrays of image engines 110 a and 110 b a smalldistance, fro example half the pixel size of the image engine along thediagonal of the pixel array, the perceived resolution of the reproducedimages can be approximately quadrupled. Operations of the image engines110 a and 110 b can be synchronized to the illumination system (102) andfeeding of the right and left images by synchronization unit 113, asshown in the figure.

It will be appreciated by those of skill in the art that a new anduseful stereoscopic display system and a method producing stereoscopicvirtual objects using the same have been described herein. In view ofthe many possible embodiments, however, it should be recognized that theembodiments described herein with respect to the drawing figures aremeant to be illustrative only and should not be taken as limiting thescope of what is claimed. Those of skill in the art will recognize thatthe illustrated embodiments can be modified in arrangement and detail.Therefore, the devices and methods as described herein contemplate allsuch embodiments as may come within the scope of the following claimsand equivalents thereof.

1. A method, comprising: producing first and second light beams that arecomposed of different numbers of colors; modulating the first and secondlight beams based upon first and second sets of image data that arerespectively derived from first and second sets of images; and passingthe modulated first and second light beams through a pair of passiveglasses with built-in first and second interference filters for viewing.2. The method of claim 1, wherein the first and second light beams arenarrow band light beams.
 3. The method of claim 2, wherein the firstlight beam comprises red, green, and blue colors.
 4. The method of claim3, wherein the first light beam further comprises yellow and cyancolors.
 5. The method of claim 2, wherein the first and second lightbeams are produced by a set of solid-state light sources that are lasersor light emitting diodes.
 6. The method of claim 3, further comprising:sequentially directing the first and second light beams onto an imageengine that modulates the first and second light beams.
 7. The method ofclaim 3, further comprising: simultaneously directing the first andsecond light beams onto an image engine that modulates the first andsecond light beams.
 8. The method of claim 2, further comprising:producing third and fourth narrowband light beams whose wavelengthspectrums substantially have no overlap; modulating the first and secondlight beams to re-produce images for a first viewer; and modulating thethird and fourth light beams to re-produce images for a second viewer.9. The method of claim 8, wherein the step of modulating the first andsecond light beams further comprises: at a first time period, modulatingthe first light beam so as to re-produce the first set of images; and ata second time period modulating the second light beam so as tore-produce the second set of images.
 10. The method of claim 9, whereinthe first and second time period are substantially equal to a frameperiod.
 11. The method of claim 2, further comprising: producing thirdand fourth narrowband light beams whose wavelength spectrumssubstantially have no overlap; modulating the first and second lightbeams so as to re-produce a portion of the first and second sets ofimages for first and second viewers; and modulating the first and secondlight beams to re-produce another portion of the first and second setsof images for first and second viewers.
 12. The method of claim 11,wherein the step of modulating the first and second light beams so as tore-produce a portion of the first and second sets of images for firstand second viewers further comprises: at a first time period, modulatingthe first light beam so as to re-produce the first portion of the firstset of images; and at a second time period, modulating the second lightbeam so as to re-produce the second portion of the first set of images.13. The method of claim 11, wherein the step of modulating the first andsecond light beams further comprises: directing the first and secondlight beams onto a first image engine; the first engine modulating thefirst and second light beams based upon at least a portion of the firstand second sets of images so as to generate first and second modulatedlight beams; and projecting the first and second modulated light beamsfrom the first image engine onto a second image engine so as tore-produce the first and second sets of images.
 14. A system capable ofproducing a stereoscopic image, the system comprising: an illuminationsystem capable of producing first and second sets of light beams,wherein the wavelengths of light of the first set are not substantiallyoverlapped with the wavelengths of light of the second set, and whereinthe first set light beams comprises a different number of colors thanthe second light beam. a color processor capable of scaling a colorspace of the stereoscopic image; an image engine for re-producing a setof images derived from the stereoscopic image by modulating the lightbeams based upon the stereoscopic image; and a passive glass with abuilt-in interference filter for separating the set of images.
 15. Thesystem of claim 14, wherein the image engine comprises an array ofmicromirrors.
 16. The system of claim 14, wherein the image enginecomprises an array of liquid-crystal cells.
 17. The system of claim 14is a front projection system.
 18. The system of claim 14 is a rearprojection system.
 19. The system of claim 14 is a backlit displaysystem.
 20. The system of claim 14, further comprising: another imageengine disposed on an optical path of the system.
 21. A method,comprising: producing first and second narrowband light beams;modulating the first and second light beams based upon first and secondsets of image data that are respectively derived from first and secondsets of images; passing the modulated first and second light beamsthrough a pair of passive glasses with built-in first and secondinterference filters for viewing such that the modulated first lightbeam is capable of passing through and substantially only the firstinterference filter; and such that the modulated second light beam iscapable of passing through and substantially only the secondinterference filter; and delivering the re-produced first set of imagesto a first viewer, and the second set of images to the second viewer forviewing.
 22. The method of claim 21, wherein the light beams arecomposed of different numbers of colors
 23. The method of claim 22,wherein the first light beam comprises red, green, blue, yellow and cyancolors.
 24. The method of claim 22, wherein the first and second lightbeams are produced by a set of solid-state light sources that are lasersor light emitting diodes.
 25. The method of claim 21, furthercomprising: producing third and fourth narrowband light beams whosewavelength spectrums substantially have no overlap; modulating the firstand second light beams to re-produce images for a first viewer; andmodulating the third and fourth light beams to re-produce images for asecond viewer.
 26. The method of claim 21, further comprising: producingthird and fourth narrowband light beams whose wavelength spectrumssubstantially have no overlap; modulating the first and second lightbeams so as to re-produce a portion of the first and second sets ofimages for first and second viewers; and modulating the first and secondlight beams to re-produce another portion of the first and second setsof images for first and second viewers.